Charred earth and twisted metal. This is what Iranian retribution looks like. Tehran fired at least 22 ballistic missiles at the the Ain al-Asad air base in Iraq, which houses U.S. forces, in retaliation for an American airstrike that took out a top Iranian military commander. One rocket knocked down more than a dozen heavy concrete blast walls and incinerated shipping containers used as living space by U.S. soldiers. Another destroyed two hangars that normally house Blackhawk helicopters, ripping through offices nearby and causing a fuel fire that lasted hours. But the damage could have been much worse. During a media walk-through, Iraqi officers station at at the base told Reuters staff began moving personnel and weaponry into fortified bunkers hours before the attack. By midnight, not as single helicopter or jet remained out in the open. And there was no loss of life. An intelligence source told Reuters that U.S. troops even seemed quote "totally aware" that the base would be hit before midnight. Early on, U.S. officials said the attack had been little more than a warning shot, allowing Iran to satisfy calls for revenge at home. But Secretary of State Mike Pompeo rejected that notion and said there was quote "no doubt" that Iran had the "full intention" of killing U.S. personnel. Speaking at Stanford on Monday, Pompeo warned Iran that the U.S. would respond if provoked.